802.11 system provides two methods for data transmission. One is MPDU aggregation, encapsulated to A-MPDU for transmitting. When MPDU to be transmitted is too long, or the channel condition is bad, it may cause failure in MPDU transmitting, to avoid the oversize data volume for re-transmission, a second method is used to carry out fragmentation of MPDU, and use the form of small fragmentation to transmit the data to the opposite terminal When the A-MPDU aggregation is used, said MPDU is the integral MPDU. When the fragmentation is used for transmitting, the fragmentation must be transmitted in single frame, not in the form of A-MPDU. The execution of the fragmentation process may also consume system resource, so the data transmission rate is relatively low, and the overall output of the system is low. Under the 802.16 system, the size negotiation of fragmentation needs the additional signaling overhead. If the fragmentation size is the same during one transmission, the efficiency of the confirmation is relatively low.
It can be seen from the above that the current data transmission methods have certain disadvantages. It is necessary to seek better solutions when faced with high demand on the speed and resource utilization rate for data transmission.